Roof leak. Three contractors, three diagnoses, three estimates. How do I know what to believe?

When it rains, sometimes some water drips through along a chimney, right at the corner where the chimney joins with the ceiling. It’s just two small spots where some water drips–not even a measured cup of drip total after even several hours of rain.

I called three different contractors to take a look.

One says it’s “the flashing.” $300

Another says it’s, IIRC, basically water leaking through old mortar. $700

Another says the whole chimney and the HVAC pipe running through it are just total crap and the whole thing needs to come down. $1500 or more

I have no idea what to think here. The latter two both say the “flashing” guy is wrong. But they’d say that if they’re trying to get my business. I just have no idea how to figure out what to thing about this, and I certainly don’t know enough to be able to figure out exactly what’s happening myself.

How do you guys get through situations like this?

Try to get some idea of what others thought about the contractors (Angie’s List, for instance). Also, how experienced are they? The “flashing” guy (phrasing?) may be new and not experienced enough to see the problem is deeper.

This is a case where you put some sealant on the expected problem area and see if that takes care of it. If so, then you wait to do anything more until you need more extensive repairs. If that doesn’t do re-flashing should take care of it. The flashing can be run up a little higher on the chimney to cover up any problems in the masonry. If you can’t go up on the roof to try out the sealant yourself then you might as well pay the guy $300 to redo the flashing.

I’d suspect the flashing first.

Are you comfortable getting on the roof? Look at the flashing around the chimney. Is it lifted up anyplace? Any gaps?

Mortar problems are very easy to confirm. you’ll see gaps in between the bricks where the mortar has fallen out. Gently use a pocket knife to test the mortar. Does it flake out easily? Is the mortar obviously loose? Repointing means the mason will remove all the loose mortar and replace with fresh. If its very, very bad they’ll take the bad top section apart and reinstall the brick with all new mortar.

If the water is travelling along the outside of the chimney, the odds are that the flashing guy is right. What the other two guys are talking about, in my opinion, would lead to water travelling inside the chimney, not along the outside surface.

Yeah unfortunately I’d apparently need to buy a $200 ladder to be able to get up there in the first place, so sayeth my friend who used to work in homebuilding.

heres a good photo. See how the mortar is flaked out in the before picture? Thats what you need to look for and confirm before paying out big bucks.

At least get the contractor to take photos of the damage before he repairs it. Then photos afterwards.

Even if there is bad mortar, am I right to think fixing the flashing would still probably basically take care of the problem? Since the water hits the flashing before it hits the mortar, right?

I am not surprised if the mortar’s bad–the thing is over a hundred years old and who knows if it’s ever been replaced before.

Most likely the flashing will fix it. A hard driving rain might get into the chimney but that would drip down into your fireplace first.

damaged flashing – Sealant won’t fix that screwed up mess. :wink:

good flashing. they did a very neat job

In commercial real estate I’ve found over time that by the time a roof leaks to the interior the issue is usually more advanced than a simply flashing repair will fix. Give it a shot but don’t be surprised if another roof issue crops up shorty thereafter.

If you own this house, you should own a ladder which can get you on the roof. This isn’t the last roofing problem you’ll have.

Can you post some pictures of the chimney and roof?

They could all be right. You could have both a failing chimney and bad flashing. I would guess the bad flashing would be the cause of this specific leak, but it’s hard to know for sure.

diagrams of how flashing is done. This helps understand what to look for when you’re on the roof.

theres step flashing and counter flashing that caps the step flashing. Counter flashing keeps water from running behind the step flashing. The counter flashing goes into the brick joint.

inspection diagram

We had exactly this issue recently. Our roof guy thought it was the old mortar in the chimney. His solution was to put a blue tarp over the top and sides of the chimney (with appropriate holes for the gas fireplace and furnace) until we decide on a permanent fix in the summer.

This seems to have been the right call. We’ve never seen the leak again, which due to its placement and numerous rain storms since then rules out the flashing.

So that’s one anecdote for you. I wouldn’t jump to thinking any of these guys are trying to rip you off. They may legitimately have differing opinions. My gut tells me that a pure roofing guy with limited experience will jump to flashing before mortar, but I could be off base on that. And the second and third opinions could just be a case of differing standards.

I’ll also note that tarps on chimneys appears to be a pretty common feature of my neighborhood. All of the houses were build in the late fifties.

The OP implies that there is a stainless steel liner inside the chimney which could indicate mortar problems have been around for a while. I will re-iterate that you only to stop the leaking now in the simplest way possible and wait to anything more until you need more extensive repairs.

If that’s a fireplace chimney you shouldn’t use it until more extensive repairs are done.

I tend to go with the flashing, the poor installation of which is the cause of most leaks. That said, moisture can wick from anywhere and only show up where it finds entry through the roof decking.

If you can get to the brickwork - even at just the ground level (another STRONG hint to get a ladder), look at the mortar - is it dry and porous-looking? If so, the stuff at the top (where the heat has been) is going to be MUCH worse.
There are at least 2 things going on:

  1. Flashing. May well be all that is required to fix the symptom (leak)
    2.The mortar has failed. Even if the mortar is NOT the cause of the leak, consider this:
    If the mortar is fixed in time, all that is required is the failed mortar is scraped out and new mortar is installed.
    If the mortar is allowed to rot, the whole thing becomes a stack of bricks, apt to literally fall over.
    This is where the workers start at the top and remove the bricks, one by one.

I have seen failed brick - the old house had plaster and lath walls - and the walls were bulging out from the weight of the loose bricks inside.
Another house had an external brick fireplace/chimney, built in the 19-teens or 20’s - it had pulled away from the house by over a foot at the top - all that could be done was dismantle it.

If the bricks need re-pointing (the term for removing/replacing the outer mortar, that is “not cheap now, but wait until you see what it will cost later” situation - even if it is not what’s causing the leak.

How long have you owned the house? Did you have it inspected before you bought it? If so, they probably paid attention to the chimney, taking pictures and describing the roof and giving an estimate of its then-current life span. If you didn’t, hiring one would cost you about $300, but you’d have a disinterested analysis by experts. If you did, but forgot what they said about the roof and lost the report, they might charge moderately to send you a copy.

As soon as I read the OP I thought, “flashing.”

I am not a contractor. But I have owned a bunch of, shall we say, vintage homes.

If you can’t get up there to fix the flashing yourself (and its ease is pretty dependant on the slope of your roof), go with that guy. If that doesn’t fix the problem, go with the next guy.

Bricks do need to be repointed occasionally, but almost anytime someone tells you “the whole thing has got to go,” there is another cheaper way to do it, even if it means doing it yourself.

But there’s usually no benefit to waiting if water is coming in; it will only get worse.